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Renesas ISL5121IB-T
- Part No.:
- ISL5121IB-T
- Manufacturer:
- Renesas
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ISL5121IB-T.pdf
- Description:
- IC SWITCH SPST-NCX2 20OHM 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,501
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Product details
Overview
ISL5121IB-T from Intersil is a dual SPST analog switch with normally closed (NC) configuration, designed for precision bidirectional signal routing in low-voltage, single-supply systems. It operates from +2.7V to +12V, delivers 19Ω ON-resistance at 5V, 28ns turn-on time, <5µW power consumption, and 10nA leakage current - enabling high-fidelity audio/video switching and portable instrumentation signal path control.
For engineers reviewing the ISL5121IB-T datasheet, ISL5121IB-T pinout, ISL5121IB-T application, or ISL5121IB-T equivalent, this page provides verified circuit role, package mapping, real-world timing behavior, leakage performance across supply voltages, and validated alternative options for NC-type dual analog switches in SOT-23.
Technical Context
The ISL5121IB-T implements two independent, bidirectional, normally closed CMOS analog switches using standard Si-gate CMOS process. Each channel features matched rON ≤1Ω, guaranteed break-before-make is not supported (unlike ISL5122/ISL5123), and logic inputs are TTL/CMOS-compatible with VIH ≥2.4V and VIL ≤0.8V across 3.3V–12V supplies.
Its internal level-shifting architecture converts digital control signals to full-rail analog gate drive, enabling rail-to-rail analog signal handling (0V to V+) without bipolar supply requirements. ESD protection exceeds 2000V per MIL-STD-883 Method 3015.7, and all pins include reverse-biased diodes to V+ and GND for overvoltage clamping.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Type | Dual SPST, normally closed (NC/NC) - both channels conduct when logic input = 0V; open when logic input ≥2.4V |
| rON @ 5V | 19Ω typical - ensures minimal signal attenuation and distortion in audio, sensor, and DAC/ADC interface paths |
| tON / tOFF | 28ns / 20ns at 5V - supports high-speed multiplexing up to ~15MHz fundamental frequency |
| Supply Range | +2.7V to +12V single supply - compatible with Li-ion, 3.3V, 5V, and 12V industrial rails without level translation |
| Leakage Current | 10nA max at 25°C - preserves accuracy in high-impedance sample-and-hold or integrator reset circuits |
| Charge Injection | 5pC max - limits voltage glitch on high-Z nodes during switching, critical for precision data acquisition |
| ESD Rating | >2000V HBM - enables robust handling in handheld and field-deployable equipment assembly |
Pinout & Package
ISL5121IB-T is housed in an 8-lead SOT-23 package (Pb-free, RoHS compliant), with thermal resistance θJA = 215°C/W. Pin numbering follows standard SOT-23 top-view orientation (pin 1 marked).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN1 | Digital control input for Switch 1 | Active-low: switch closes (NC→COM) when IN1 ≤0.8V; opens when IN1 ≥2.4V |
| NO1 | Normally open terminal of Switch 1 | Unconnected in default state; no internal connection unless switch is forced ON (not applicable to ISL5121) |
| COM1 | Analog common node of Switch 1 | Signal path endpoint - bidirectionally connected to NC1 when IN1 = low |
| NC1 | Normally closed terminal of Switch 1 | Default conduction path to COM1; disconnects only when IN1 driven high |
| GND | Ground reference | Return path for supply and logic; must be tied before applying analog signals |
| V+ | Positive supply rail | Single power source for analog path and internal logic; sets analog signal range (0V to V+) |
| NC2 | Normally closed terminal of Switch 2 | Independent NC path for second channel; identical behavior to NC1 under IN2 control |
| IN2 | Digital control input for Switch 2 | Independent logic input - enables asynchronous control of second NC switch |
Key Features
| Feature | Design Value |
|---|---|
| Dual NC topology | Enables fail-safe signal routing where default-closed paths ensure continuity during power loss or logic fault |
| Low rON matching (≤1Ω) | Minimizes gain error and crosstalk in differential or parallel-switched sensor interfaces |
| Sub-5µW quiescent power | Extends battery life in always-on monitoring circuits without compromising switching speed |
| 3.3V/5V/12V full specification | Eliminates requalification effort when migrating between voltage domains in multi-rail systems |
| 6 Ld & 8 Ld SOT-23 options | ISL5121IB-T uses 8-lead SOT-23 - retains full dual-channel functionality while optimizing board space vs SOIC |
Applications
| Audio Signal Routing | Portable Medical Instrumentation |
|---|---|
Use Scenario: Selecting between multiple microphone inputs or headphone outputs in a smartphone or VoIP handset. IC Role / Device Role / Timing Role: Dual NC analog switch providing low-distortion, low-noise signal path selection with <28ns settling. Use Value: 19Ω rON and 5pC charge injection prevent audible pop/click and preserve SNR in 24-bit audio chains. | Use Scenario: Multiplexing ECG electrode leads into a single ADC front-end in a wearable cardiac monitor. IC Role / Device Role / Timing Role: Precision analog switch isolating high-impedance biopotential sources during channel scanning. Use Value: 10nA leakage and rail-to-rail analog range maintain DC accuracy and baseline stability across ±5mV signals. |
| Industrial Sensor Interface | Test Equipment Signal Conditioning |
Use Scenario: Switching between RTD, thermocouple, and strain gauge inputs in a handheld multimeter or data logger. IC Role / Device Role / Timing Role: Dual NC switch enabling automatic sensor calibration by shorting reference paths during self-test. Use Value: Matched rON ≤1Ω ensures consistent gain scaling across channels; 2.7V operation supports coin-cell backup. | Use Scenario: Configuring input impedance (50Ω/1MΩ) and signal path (AC/DC coupling) in a portable oscilloscope front-end. IC Role / Device Role / Timing Role: High-speed analog switch managing signal routing prior to amplification and digitization stages. Use Value: 76dB off-isolation and -105dB crosstalk suppress feedthrough in multi-channel 100MHz bandwidth designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual NC analog switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISL5120IHZ-T | Dual NO configuration (not NC); otherwise identical rON, timing, and package | Requires active-high enable for signal path closure; unsuitable for fail-closed safety-critical paths | Select only if system logic drives high to activate - not a drop-in replacement for NC functionality |
| TMUX1574RTER | Single-supply, dual NC switch with 4.5Ω rON @ 5V; 1.8V–5.5V range; 10-pin WQFN | Lower rON but narrower supply range; requires PCB redesign due to different footprint and pinout | Prefer for ultra-low-loss 3.3V systems where layout change is acceptable |
Compared with ISL5121IB-T, ISL5120IHZ-T provides identical performance in NO mode but cannot replicate fail-closed behavior, while TMUX1574RTER offers lower resistance and modern packaging at the cost of supply flexibility and mechanical compatibility.
Availability
ISL5121IB-T is available at Aetrix Electronics and suitable for battery-powered handheld equipment, portable medical instrumentation, and industrial sensor interface designs requiring stable component supply across extended temperature ranges (-40°C to +85°C).
Supply support for ISL5121IB-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Intersil Corporation is a semiconductor manufacturer specializing in precision analog and power management ICs, now part of Renesas Electronics.
The ISL512x family was engineered for low-voltage, low-power analog signal routing in portable and space-constrained systems - emphasizing rail-to-rail operation, nanosecond switching, and ultra-low leakage without external support components.
FAQ
What is the function of the NC pins on the ISL5121IB-T?
The NC (Normally Closed) pins - NC1 and NC2 - form the default-conducting path to their respective COM pins when the corresponding IN pin is logic low (≤0.8V). Unlike NO switches, the ISL5121IB-T maintains continuity without active drive, making it suitable for safety-critical or default-on signal routing. When IN is raised to ≥2.4V, the NC–COM path opens. The NO pins are unconnected and unused in this variant.
Does the ISL5121IB-T support rail-to-rail analog signal operation?
Yes, the ISL5121IB-T supports rail-to-rail analog signal operation from 0V to V+, provided V+ is within its specified range (+2.7V to +12V). This is enabled by its internal level-shifting architecture, which drives switch gates to full V+ and GND potentials. Signal voltages exceeding V+ or falling below GND are clamped by internal ESD diodes - so analog inputs must remain within those bounds for linear operation.
Can the ISL5121IB-T be used with a 1.8V logic controller?
No - the ISL5121IB-T requires VIH ≥2.4V and VIL ≤0.8V for guaranteed logic recognition, and its minimum supply is +2.7V. A 1.8V controller cannot meet the 2.4V high-threshold requirement. To interface with 1.8V logic, a level shifter (e.g., TXB0104) or a compatible 1.8V-tolerant analog switch like the TMUX1574 must be used instead of the ISL5121IB-T.
What is the maximum analog signal frequency supported by the ISL5121IB-T?
The ISL5121IB-T maintains usable signal integrity beyond 100MHz in 50Ω systems, with off-isolation >50dB and crosstalk <−105dB at 1MHz. Its −3dB bandwidth exceeds 300MHz under optimal conditions (V+ = 5V, RL = 50Ω). However, effective usable frequency depends on load impedance and layout - for 10-bit+ accuracy in multiplexed ADC applications, keep analog frequencies below 10MHz to minimize charge injection and rON flatness effects.
Is the ISL5121IB-T pin-compatible with other devices in the ISL512x family?
Yes - all ISL512x variants (ISL5120, ISL5121, ISL5122, ISL5123) in the 8-lead SOT-23 package share identical pinouts and footprints. The ISL5121IB-T can be substituted with ISL5120IHZ-T or ISL5122IHZ-T on the same PCB, though functional behavior differs: ISL5120 is dual NO, ISL5122 is NO/NC (SPDT-capable), and ISL5121IB-T remains the only dual NC option in this pinout.
ISL5121IB-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Switch Circuit:
- SPST - NC
- Multiplexer/Demultiplexer Circuit:
- 1:1
- Number of Circuits:
- 2
- On-State Resistance (Max):
- 20Ohm
- Channel-to-Channel Matching (ΔRon):
- 800mOhm
- Voltage - Supply, Single (V+):
- 2.7V ~ 12V
- Voltage - Supply, Dual (V±):
- -
- Switch Time (Ton, Toff) (Max):
- 35ns, 30ns
- -3db Bandwidth:
- -
- Charge Injection:
- 5pC
- Channel Capacitance (CS(off), CD(off)):
- 8pF, 8pF
- Current - Leakage (IS(off)) (Max):
- 100pA
- Crosstalk:
- -105dB @ 1MHz
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
ISL5121IB-T FAQ
1.How can I place an order for ISL5121IB-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL5121IB-T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ISL5121IB-T reliable?
The price and inventory of ISL5121IB-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL5121IB-T is usually 5 days.
3.What payment methods are accepted for ISL5121IB-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL5121IB-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL5121IB-T?
ISL5121IB-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL5121IB-T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ISL5121IB-T?
For technical support, including ISL5121IB-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL5121IB-T requirements.
6.How does Aetrix verify that ISL5121IB-T is sourced from the original manufacturer or authorized distributors?
All ISL5121IB-T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ISL5121IB-T meets industry standards.
7.What is the process for return or replacement of ISL5121IB-T?
All ISL5121IB-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL5121IB-T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ISL5121IB-T part is unused and in its original packaging.
Return procedure for ISL5121IB-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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